smoke and ….

Eric Hu, from Melbourne’s Deakin University, said that while red house roofs absorbed heat from the sun, white ones would bounce energy back into space and “it will never come back”.

He also proposed painting roads white, and building giant mirrors in the outback. He said energy reflectors could be built in the desert using aluminium foil, “like you use in the kitchen”.

A climate change expert at the University of NSW, Andy Pitman, said Dr Hu’s ideas were “not stupid” but required more research to ensure there would be no unwanted side-effects. But better than reflecting energy would be to harness it using roof tiles with built-in solar cells.

Dr Pitman suspected white roads and roofs could inflict glare on motorists and said scientists would need to be sure heat reflected from outback mirrors did not interfere with the weather.